1464.sn 74hc4060.docx
We have a probleme with the SN 74HC60.
We use it as a counter. with an rc oscillator. The freq on pin 9 is about 157hz
We have not a good stability on signal on Q4(pin7).
R2=510k on pin 11
R1=270k on pin 10
C=10nF on pin 9
When we use another component (the 74HC4060) ther's no problem with these values.
Is there limits on components R1,R2,C for the SN 74HC60
Patrice
patrice caslot 1464.sn 74hc4060.docx the yellow is the freq in pin 9 the red signal is the bad signal en pin7. It should be Q4=Pin7=freq 157hz/16 ! We have a probleme with the SN 74HC60. We use it as a counter. with an rc oscillator. The freq on pin 9 is about 157hz We have not a good stability on signal on Q4(pin7). R2=510k on pin 11 R1=270k on pin 10 C=10nF on pin 9 When we use another component (the 74HC4060) ther's no problem with these values. Is there limits on components R1,R2,C for the SN 74HC60 Patrice
the yellow is the freq in pin 9
the red signal is the bad signal en pin7. It should be Q4=Pin7=freq 157hz/16 !
Hi Patrice
We do not make a 74HC60 that I can find.
Hi chris
Im' sorry it's the 74HC4060 !
Here is the two datasheet of the component we use from texas
The oscillator is ok with the cd74HC4060
It is bad with the SN74HC4060
2677.sn74hc4060.pdf
5775.texas instruments cd74HC4060E.pdf
In general there are almost no differences between the SN and CD devices. However this is the only one I know of that truly shows a difference. Looking at the attached waveforme it looks like the CD device has very weak or unbuffered outputs while the SN device shows sharp edges and shows to be buffered.
So even though they function the same their outputs characteristics are different.
The real problem is that the sn component don't do his job. He don't follow his logic diagram which is in the page 2 of the data sheet.The yellow signal show the pin 9 (clock0) and the red signal show the pin 7(QD) .QD should be clk0/16 ! and he is not!.There s an anstability we don't explain!